| 释义 |
▪ I. per-, prefix1
The Latin preposition per (see prec.) used in composition with verbs, adjectives, and their derivatives. A large number of these have come down through Fr. into Eng.; others have been adopted directly from Lat., or formed in Eng. on Latin elements, or (as was frequent in 16–17th c.) on words already in Eng. use. The following are the chief uses in Latin and English.
I. As an etymological element. In the senses:
1. Through, in space or time; throughout, all over: with verbs (and their derivatives), as perambulāre to walk through, perambulate, perforāre to bore through, perforate, pervadĕre to go through, pervade, pervigilāre to watch through, pervigilate; forming adjs., as pervius having a way through, pervious.
2. Through and through, thoroughly, completely, to completion, to the end: with verbs (and derivatives), as perficĕre to do thoroughly, complete, perfect, permūtāre to change throughout or completely, permute, perpetrāre to perpetrate, perturbāre to perturb; so peruse, etc.
3. Away entirely, to destruction, ‘to the bad’: with verbs (and derivatives), as perdĕre to do away with, destroy, lose (perdition), perīre to go to destruction, perish, pervertĕre to turn away evilly, pervert, perimĕre to take away entirely, destroy, annihilate (peremptory).
4. Thoroughly, perfectly, extremely, very: with adjs. and advbs., as peracūtus very sharp, peracute, perdīligens very diligent, perdiligent, perfervidus, perfervid. Formerly also in Eng. with derived ns. (or their analogues), in sense ‘very great’, ‘extreme’, as perdiligence, peradvertence.
II. In Chemical nomenclature. (From 4 above.)
5. Forming ns. and adjs. denoting the maximum (or supposed maximum) of some element in a chemical combination; esp.a. With names of binary compounds in -ide (formerly -uret), designating that in which the element or radical combines in the largest proportion with another element, e.g. peroxide, perchloride († perchloruret), per-iodide, persulphide († persulphuret), q.v. Also perˈbromide († perˈbromuret), a compound of bromine with another element or radical, in which the bromine is present in larger proportion than in other compounds: so perˈcyanide († per-cyˈanuret), perphosphide († per-phosphuret), etc. Hence in derivative verbs, etc.: as peroxidate, -oxidize, perphosphuretted, etc.
This use of per- was introduced in 1804 by Dr. T. Thomson, in his System of Chemistry, ed. 2, for combinations of oxygen with a metal, peroxide being used to indicate ‘that the metal is thoroughly oxidized’, or ‘combined with as much oxygen as possible’: see peroxide. It was subsequently extended to combinations of other elements, as perchloride, etc. In strict chemical nomenclature names in per- have been to a great extent superseded by those with more definite numerical prefixes (e.g. peroxide of manganese by manganese dioxide), or by others in which the constitution of the substance is differently expressed (e.g. perchloride and peroxide of iron, by ferric chloride, ferric oxide). But the per- compounds are retained in some cases, especially in pharmacy and popular use.
b. With adjs. in -ic, naming oxides, acids, etc., designating that compound which contains the greatest proportion of oxygen (and, consequently, the least of the element named), as perˈbromic perbromic acid, hydrogen perbromate, HBrO4; perˈchromic perchromic acid, H2Cr2O8; periˈridic periridic oxide, iridium trioxide, IrO3; perˈnitric pernitric acid, HNO4; peˈrosmic perosmic acid (= oxide), OsO4; perruˈthenic perruthenic acid (= oxide), RuO4, etc. See also perchloric, -iodic, -manganic, etc. Also in names of the salts of these acids, and analogous bodies, as perchlorate, -iodate, -manganate, -sulphate, q.v., perˈchromate, periˈridiate, perˈnitrate, perˈphosphate, perˈtitanate, etc.
Many of these also are now abandoned for names otherwise formed; e.g. pernitrate of iron, of mercury, now ferric and mercuric nitrate.
Formerly per- was also prefixed to adjs. in -ous, where hypo- is now used, as persulphurous = hyposulphurous; so pernitrous, perphosphorous.
1804[see peroxide]. 1813[see persulphate]. 1818[see perchloric, perchloride]. 1818Henry Elem. Chem. (ed. 8) I. 405 When 400 measures of nitrous gas and 100 measures of oxygen..are mixed together..we obtain 100 measures of a compound, called by Gay Lussac per-nitrous acid. Mr. Dalton..has lately proposed to call it sub-nitrous acid. Ibid. II. 12 Hypo-phosphorous or Per-phosphorous Acid. 1819[see periodide]. 1826Henry's Chem. II. 129 A solution is obtained, in which the metal is more highly oxidated, constituting per-nitrate of mercury. 1836J. M. Gully Magendie's Formul. (ed. 2) 124 Perbromuret of Iron..is a brick-red salt, very soluble, deliquescent. 1836Brande Chem. (ed. 4) Index, Perbromide, Perfluoride. Ibid. 771 The chromate of the peroxide of iron (perchromate) is soluble. 1842Parnell Chem. Anal. (1845) 347 The soluble double compound of percyanide of cobalt and cyanide of potassium (cobalti-cyanide of potassium). 1849D. Campbell Inorg. Chem. 272 [They] leave, on washing with water, a pertitanate of the alkali. 1854J. Scoffern in Orr's Circ. Sc., Chem. 449 Solutions containing perchromic acid possess a beautiful blue tint. 1866Roscoe Elem. Chem. 102 Perbromic Acid, or Hydric Perbromate..obtained by the action of bromine upon perchloric acid. 1868Watts Dict. Chem. V. 138 Tetroxide of ruthenium, RuO4, Ruthenic tetroxide, Perruthenic acid. 1873Fownes' Chem. (ed. 11) 436 A deep indigo-coloured solution of basic potassium periridiate. Ibid., The trioxide, or Periridic oxide, is not known in the free state. 1876Harley Mat. Med. (ed. 6) 85 Adding again half as much bromine, the perbromide is formed. Ibid. 215 Iron combines with a portion of the nitric acid to form a soluble pernitrate. 1877Athenæum 1 Dec. 702/2 Mounting for the microscope specimens of small animals which have been hardened in perosmic acid. 1880E. Cleminshaw Wurtz' Atom. The. 233 In perruthenic acid and in osmic acid..ruthenium and osmium act as octovalent elements. 1882Athenæum 13 May 607/1 They find that ozone prepared by the electrization of dry air is mixed with another gaseous compound, ‘pernitric acid’. The formation of this acid is limited, like that of ozone, by a given temperature.
▪ II. per-, prefix2
representing OF. per or F. par (see par prep., per prep. II), in phrases which have coalesced into single words, as peradventure, percase, perchance, etc.; so also (with second element Eng.) perhaps. |